1. Field of the Invention
This invention relates to liquid waste disposal and more particularly refers to a new and improved method and apparatus for treating liquid waste contaminated with volatile radioactive substances.
2. Description of the Prior Art
In nuclear power stations water is used for many purposes such as cooling water, boiler water and turbine steam. Some of the waste water collected from these sources contain impurities, particularly volatile radioactive substances which create a problem. The usual practice was to evaporate the liquid in a still fitted with a bubble-cap column. It was found, however, that purification could not be adequately accomplished even if the waste water were acidified because of the carryover of volatile contaminants. Resort was had to subjecting the partially purified waste water to another treatment in another still equipped with a bubble-cap column but in the second operation employing a liquid of different pH, e.g. alkaline liquid. While this procedure satisfactorily purified the waste water, it does involve two operations with two stills and corresponding bubble-cap columns, which equipment is expensive, in view of the corrosion resistant material required, costing $40,000.00 and up per unit.